5 ms·

Haskell web framework IHP aims to make web development type-safe and easy

88 points by _query 6y ago

all_factz 6y ago
This is the first Haskell web development framework (granted, I haven’t looked at very many) that would actually make me interested in trying web dev in Haskell. Coming from a Django/PHP background, it seems it provides a lot of desirable functionality and type-safety out of the box while also being relatively comprehensible for a Haskell newbie.
- oever 6y ago
  A few years back, I used Yesod. It was very nice because of the type-safety from top to bottom. Especially nice in combination with esqueleto. https://www.yesodweb.com/book https://www.yesodweb.com/book
  - iso8859-1 6y ago
    Did you try Opaleye? This guy seems to prefer it: https://williamyaoh.com/posts/2019-12-14-typesafe-db-libraries.html https://williamyaoh.com/posts/2019-12-14-typesafe-db-librari...
    - oever 6y ago
      I had not heard of Opaleye yet.
  - whateveracct 6y ago
    Esqueleto and persistent are quite nice. Their one downside is SqlPersistT. The abstraction makes sense, but once you have people putting that thing as the base Monad in your stack, you're in trouble. Its nature means it holds a transaction (and therefore connection!) open during the entire action if used that way. This will cause big problems, like causing requests to queue on your connection pool if some other IO/parts of the code are slow and hogging the connection.
- _query 6y ago
  Many people in the IHP community are beginning their haskell journey with IHP. Check out e.g. 100 days of haskell by Lars Ulvestad: https://driftercode.com/blog/hundred-days-of-haskell-day-one/ https://driftercode.com/blog/hundred-days-of-haskell-day-one... Started around 60 days ago, and now here's the soon-to-be-production app: https://twitter.com/larsparsfromage/status/1314998566776172547 https://twitter.com/larsparsfromage/status/13149985667761725... :)
embwbam 6y ago
This looks well done, but having used Haskell professionally on multiple web projects, I have to take issue with some of the design choices. Templating? Haskell provides such a wonderfully clean way to generate HTML via combinators and do notation. You don't need a quasi quoter to get a DSL. See Lucid. All templating does is remove control features (like forM, for example). [1] They've reinvented common operators. For example, (|>), which is great, I've used it in Elm, but the Haskell version of this is (&) from Data.Function. These are just a few examples. They're ignoring Haskell conventions to make it more familiar to people coming from other backgrounds, even when the community conventions are strictly better or equal. Rails was a nightmare for me, it was impossible to tell what was a language feature and what came from the framework. I suspect this will equivalently speed up initial development while slowing understanding. [1] https://mmhaskell.com/blog/2020/3/16/lucid-another-html-option https://mmhaskell.com/blog/2020/3/16/lucid-another-html-opti...
- _query 6y ago
  > Templating? Haskell provides such a wonderfully clean way to generate HTML via combinators and do notation. You don't need a quasi quoter to get a DSL. See Lucid. All templating does is remove control features (like forM, for example). IHP's templating HSX is targeted at people with a react background that are familiar with JSX syntax. In the background it compiles down to blaze-html and can be used together with e.g. forM_ (which we have aliased to forEach). It's just a more familiar syntax on top of blaze html. Some internal IHP functions are even still implemented with the blaze combinators: https://github.com/digitallyinduced/ihp/blob/master/IHP/View/TimeAgo.hs#L79 https://github.com/digitallyinduced/ihp/blob/master/IHP/View... > They've reinvented common operators. For example, (|>), which is great, I've used it in Elm, but the Haskell version of this is (&) from Data.Function. The |> just looks more beautiful to us :) Take a look at the gorgeous expressiveness of this: https://twitter.com/digitallyinduce/status/1299070906854248448 https://twitter.com/digitallyinduce/status/12990709068542484... > They're ignoring Haskell conventions to make it more familiar to people coming from other backgrounds, Yes, IHP is the haskell framework for builders :-)
  - embwbam 6y ago
Kaze404 6y ago
I tried this a couple weeks ago and while the process was rather smooth (as a newcomer to Haskell), the process to add authentication to the application was not explained at all in the docs -- they just have you copy and paste a bunch of code. Hopefully that can be improved in the future :)
- _query 6y ago
  Good point! We're working on improvements to this :-) We actually had a conversation about this in the office a couple hours ago. There's also an GH issue for this already: https://github.com/digitallyinduced/ihp/issues/467 https://github.com/digitallyinduced/ihp/issues/467
  - Kaze404 6y ago
    Awesome. Keep up the good work!
q3k 6y ago
I've tried this out a few days ago. I have some basic theoretical Haskell knowledge, but not much practical experience. However I do have some significant Nix experience. Ended up not even going through the beginner tutorial, as the installer/scaffold process required me to do things that I didn't like: - forced scaffolding of projects with some quite blackboxy generated shell scripts inside - use of nix, yet requiring me to install 'make' and 'direnv' system-wide (why? just let me use a shell.nix) - required me to use cachix.org as a system-wide nix substituter, which I don't want to do for security reasons (just allow me to build everything myself) All in all this looked promising, but ended up being too magical for my taste. I'd like to be able to start using IHP 'from scratch' instead - with my own Cabal/Nix/Bazel build machinery. This is a critical requirement for libraries/frameworks that I use. Your mileage may vary though - if you're okay with RoR-like scaffolding and blackboxness, then you might feel at home here, and at least you get a nicely typed language in return.
- the_french 6y ago
  I think replicating RoR in Haskell is explicitly the goal of IHP. I don't have a problem with them making opinionated choices for projects, I really don't want to have to wade through library choices and configuration each time I start a project. Granted I started out as a Rails dev...
  - q3k 6y ago
    > I really don't want to have to wade through library choices and configuration each time I start a project. I think this is a false dichotomy. You certainly can have an opinionated way to setup a project that 90% of people use at first, with some way to customize things as you go along, or at least a way to replicate the standard setup with whatever tooling is more conducive to the user's vision. Flask is a good example of this. You start out with a minimal single-file app, with a somewhat magical tool (`flask`) that will take care of starting a debug server for you and whatnot. As you go along, you can grow your app according to the official manual ('project layout', 'growing big' manual pages, using blueprints and application factories and other typical Flask patterns), or you can do something that fits more to your existing codebase. You can also keep using the `flask` tool, or write your own equivalent. Or skip it entirely and express everything as Python scripts. Even with the quite more complex and scaffoldy Django, you're very much able to rejigger a scaffolded app easily into whatever structure you want, as long as you're ready to dust off the “Forbidden PYTHONPATH and DJANGO_SETTINGS tricks” book.
claudiulodro 6y ago
I work with commodity LAMP-style hosting mostly, so I'm not familiar with this sort of framework. How involved is setting up and running a Haskell web server? Is it a fully bespoke thing that needs to be figured out, or is it just like an image you install? Is this stuff generally hosted on standard clouds (e.g. AWS)? IMO the server setup seems to be the biggest issue with these sorts of boutique web frameworks, but I'd love to learn more if I'm incorrect.
- _query 6y ago
  IHP apps are generally deployed on standard Cloud such as AWS. In the big picture you need to build the binary and CSS+JS and then copy the files onto your production server. There you just need to start the binary and pass some options (such as the DB connection) via env parameters. Check the deployment guide for more details: https://ihp.digitallyinduced.com/Guide/deployment.html https://ihp.digitallyinduced.com/Guide/deployment.html There's also IHP Cloud which is basically "netlify for haskell". Here's a video of deploying a IHP haskell app in 60 seconds: https://twitter.com/digitallyinduce/status/1313410469785407488 https://twitter.com/digitallyinduce/status/13134104697854074... More infos here: https://ihpcloud.com/ https://ihpcloud.com/
AlexITC 6y ago
While IHP looks nice, it will certainly take a while to get into a similar shape to scalajs, in any case, I'm happy to see more work on the typed side for web development. For anyone interested, Web Development is already Type-Safe and Easy by leveraging scala-js.org, being an amazing project. It was the first project in the area to get amazing IDE support for free, where even TypeScript took a while to catch-up, and I still personally believe the auto-completion /refactor/navigation support is better in scalajs. For people not familiar, take a look to this js to sjs comparison: https://www.scala-js.org/doc/sjs-for-js/ https://www.scala-js.org/doc/sjs-for-js/ My preferred tech stack is now https://scalablytyped.org https://scalablytyped.org (like definitelytyped for Scala), https://slinky.dev/ https://slinky.dev/ (a small react wrapper), and https://material-ui.com/ https://material-ui.com/, which makes me work on the frontend at an incredible speed, while being confident on a low-bug rate.
kodefant 6y ago
I have been learning Haskell through IHP. It's the best and actually simplest web framework I have ever tried. The developer experience is the best I ever had for a MVC-style framework. And I got to learn Haskell without banging my head too much against the wall. Really enjoyed it :) I really needed something like IHP to get started with Haskell. It's fun and easy and the documentation is very easy to follow. I see some argue that they wish to make more custom choices regarding the setup. That is precisely what I don't want and that's why IHP is a great fit for me. In terms of simplicity I think the choice of supporting only Nix and Postgres actually are strengths at this point. That lets them streamline the development of the framework without supporting the minor preferences of every individual. And these choices should work really well for most web developers. Some may disagree on this, and maybe IHP is not for them, but I don't think it shouldn't discourage those who considers trying it out and form their own opinion. I was prepared for great hardships learning Haskell as most of the resources are very academic and I'm mainly just a simple application builder. IHP was just what I needed to fill that gap, and it made it really fun :) I am tweeting about the whole thing, coding Haskell for 100 days: https://twitter.com/larsparsfromage https://twitter.com/larsparsfromage
ljm 6y ago
I gave this a shot, to see if it'd be better than writing my API with Servant and then building a client separately. It looks really cool and there's been a lot of work put into it, so I had to see for myself. I kind of wish it didn't depend on Nix and Cachix and stuff like that, compared to deploying as a Stack template. I can see how it simplifies setup of a lot of the environment but considering the various issues I had trying to run it through WSL2, it left me at a point where I couldn't really understand what was going wrong. I'm back to messing around with Servant, but that's also because I'm not the target user for rapid web dev in this case. I want to learn Haskell my own way.
montmorency88 6y ago
IHP is the best web framework experience I have had. I think a lot of aspiring haskeller's will have worked their way through a text like Learn You a Haskell For Great Good or similar and then be looking to fool around with an actual project. IHP uses nix to cut out all the work of setting up ghc/stack/cabal which can be quite tricky for a beginner, it has just added haskell language server integration, it starts your postgres servers, it spares you from having to remember your SQL syntax, and means you can start writing haskell code instantly while getting immediate feedback on your hacking from GHCi and visually through the live reloading of the web app in your browser. I've found the [hsx||] quasiquotes quite fun to work with and type safety has sped up development by preventing bugs that can easily crop up when you're linking forms to databases. I like the design choices in IHP, and for me, at the moment, I like the focus on server side web app development, which encourages you to be more sparing/judicious in the use of javascript. With IHP being opinionated about the models/views and routing it means I can focus on integrating some of the other really cool haskell libraries that exist into web apps. (I'm also trying to keep a log of my experiences here on an https://ihpcafe.ihpapp.com https://ihpcafe.ihpapp.com if you want to read along with someone figuring out function type signatures ;) )
nsonha 6y ago
Jsx is a plague. What's wrong with simply nesting function calls like in elm and fsharp? Someone goes this far to learn a rather eccentric language you think they care about superficial familarities?

88 points by _query 6y ago

This is the first Haskell web development framework (granted, I haven’t looked at very many) that would actually make me interested in trying web dev in Haskell. Coming from a Django/PHP background, it seems it provides a lot of desirable functionality and type-safety out of the box while also being relatively comprehensible for a Haskell newbie.

oever 6y ago
A few years back, I used Yesod. It was very nice because of the type-safety from top to bottom. Especially nice in combination with esqueleto. https://www.yesodweb.com/book https://www.yesodweb.com/book
- iso8859-1 6y ago
  Did you try Opaleye? This guy seems to prefer it: https://williamyaoh.com/posts/2019-12-14-typesafe-db-libraries.html https://williamyaoh.com/posts/2019-12-14-typesafe-db-librari...
  - oever 6y ago
    I had not heard of Opaleye yet.
- whateveracct 6y ago
  Esqueleto and persistent are quite nice. Their one downside is SqlPersistT. The abstraction makes sense, but once you have people putting that thing as the base Monad in your stack, you're in trouble. Its nature means it holds a transaction (and therefore connection!) open during the entire action if used that way. This will cause big problems, like causing requests to queue on your connection pool if some other IO/parts of the code are slow and hogging the connection.
_query 6y ago
Many people in the IHP community are beginning their haskell journey with IHP. Check out e.g. 100 days of haskell by Lars Ulvestad: https://driftercode.com/blog/hundred-days-of-haskell-day-one/ https://driftercode.com/blog/hundred-days-of-haskell-day-one... Started around 60 days ago, and now here's the soon-to-be-production app: https://twitter.com/larsparsfromage/status/1314998566776172547 https://twitter.com/larsparsfromage/status/13149985667761725... :)

embwbam 6y ago

This looks well done, but having used Haskell professionally on multiple web projects, I have to take issue with some of the design choices. Templating? Haskell provides such a wonderfully clean way to generate HTML via combinators and do notation. You don't need a quasi quoter to get a DSL. See Lucid. All templating does is remove control features (like forM, for example). [1] They've reinvented common operators. For example, (|>), which is great, I've used it in Elm, but the Haskell version of this is (&) from Data.Function. These are just a few examples. They're ignoring Haskell conventions to make it more familiar to people coming from other backgrounds, even when the community conventions are strictly better or equal. Rails was a nightmare for me, it was impossible to tell what was a language feature and what came from the framework. I suspect this will equivalently speed up initial development while slowing understanding. [1] https://mmhaskell.com/blog/2020/3/16/lucid-another-html-option https://mmhaskell.com/blog/2020/3/16/lucid-another-html-opti...

_query 6y ago
> Templating? Haskell provides such a wonderfully clean way to generate HTML via combinators and do notation. You don't need a quasi quoter to get a DSL. See Lucid. All templating does is remove control features (like forM, for example). IHP's templating HSX is targeted at people with a react background that are familiar with JSX syntax. In the background it compiles down to blaze-html and can be used together with e.g. forM_ (which we have aliased to forEach). It's just a more familiar syntax on top of blaze html. Some internal IHP functions are even still implemented with the blaze combinators: https://github.com/digitallyinduced/ihp/blob/master/IHP/View/TimeAgo.hs#L79 https://github.com/digitallyinduced/ihp/blob/master/IHP/View... > They've reinvented common operators. For example, (|>), which is great, I've used it in Elm, but the Haskell version of this is (&) from Data.Function. The |> just looks more beautiful to us :) Take a look at the gorgeous expressiveness of this: https://twitter.com/digitallyinduce/status/1299070906854248448 https://twitter.com/digitallyinduce/status/12990709068542484... > They're ignoring Haskell conventions to make it more familiar to people coming from other backgrounds, Yes, IHP is the haskell framework for builders :-)
- embwbam 6y ago

Kaze404 6y ago

I tried this a couple weeks ago and while the process was rather smooth (as a newcomer to Haskell), the process to add authentication to the application was not explained at all in the docs -- they just have you copy and paste a bunch of code. Hopefully that can be improved in the future :)

_query 6y ago
Good point! We're working on improvements to this :-) We actually had a conversation about this in the office a couple hours ago. There's also an GH issue for this already: https://github.com/digitallyinduced/ihp/issues/467 https://github.com/digitallyinduced/ihp/issues/467
- Kaze404 6y ago
  Awesome. Keep up the good work!

q3k 6y ago

I've tried this out a few days ago. I have some basic theoretical Haskell knowledge, but not much practical experience. However I do have some significant Nix experience. Ended up not even going through the beginner tutorial, as the installer/scaffold process required me to do things that I didn't like: - forced scaffolding of projects with some quite blackboxy generated shell scripts inside - use of nix, yet requiring me to install 'make' and 'direnv' system-wide (why? just let me use a shell.nix) - required me to use cachix.org as a system-wide nix substituter, which I don't want to do for security reasons (just allow me to build everything myself) All in all this looked promising, but ended up being too magical for my taste. I'd like to be able to start using IHP 'from scratch' instead - with my own Cabal/Nix/Bazel build machinery. This is a critical requirement for libraries/frameworks that I use. Your mileage may vary though - if you're okay with RoR-like scaffolding and blackboxness, then you might feel at home here, and at least you get a nicely typed language in return.

the_french 6y ago
I think replicating RoR in Haskell is explicitly the goal of IHP. I don't have a problem with them making opinionated choices for projects, I really don't want to have to wade through library choices and configuration each time I start a project. Granted I started out as a Rails dev...
- q3k 6y ago
  > I really don't want to have to wade through library choices and configuration each time I start a project. I think this is a false dichotomy. You certainly can have an opinionated way to setup a project that 90% of people use at first, with some way to customize things as you go along, or at least a way to replicate the standard setup with whatever tooling is more conducive to the user's vision. Flask is a good example of this. You start out with a minimal single-file app, with a somewhat magical tool (`flask`) that will take care of starting a debug server for you and whatnot. As you go along, you can grow your app according to the official manual ('project layout', 'growing big' manual pages, using blueprints and application factories and other typical Flask patterns), or you can do something that fits more to your existing codebase. You can also keep using the `flask` tool, or write your own equivalent. Or skip it entirely and express everything as Python scripts. Even with the quite more complex and scaffoldy Django, you're very much able to rejigger a scaffolded app easily into whatever structure you want, as long as you're ready to dust off the “Forbidden PYTHONPATH and DJANGO_SETTINGS tricks” book.

claudiulodro 6y ago

I work with commodity LAMP-style hosting mostly, so I'm not familiar with this sort of framework. How involved is setting up and running a Haskell web server? Is it a fully bespoke thing that needs to be figured out, or is it just like an image you install? Is this stuff generally hosted on standard clouds (e.g. AWS)? IMO the server setup seems to be the biggest issue with these sorts of boutique web frameworks, but I'd love to learn more if I'm incorrect.

_query 6y ago
IHP apps are generally deployed on standard Cloud such as AWS. In the big picture you need to build the binary and CSS+JS and then copy the files onto your production server. There you just need to start the binary and pass some options (such as the DB connection) via env parameters. Check the deployment guide for more details: https://ihp.digitallyinduced.com/Guide/deployment.html https://ihp.digitallyinduced.com/Guide/deployment.html There's also IHP Cloud which is basically "netlify for haskell". Here's a video of deploying a IHP haskell app in 60 seconds: https://twitter.com/digitallyinduce/status/1313410469785407488 https://twitter.com/digitallyinduce/status/13134104697854074... More infos here: https://ihpcloud.com/ https://ihpcloud.com/

AlexITC 6y ago

While IHP looks nice, it will certainly take a while to get into a similar shape to scalajs, in any case, I'm happy to see more work on the typed side for web development. For anyone interested, Web Development is already Type-Safe and Easy by leveraging scala-js.org, being an amazing project. It was the first project in the area to get amazing IDE support for free, where even TypeScript took a while to catch-up, and I still personally believe the auto-completion /refactor/navigation support is better in scalajs. For people not familiar, take a look to this js to sjs comparison: https://www.scala-js.org/doc/sjs-for-js/ https://www.scala-js.org/doc/sjs-for-js/ My preferred tech stack is now https://scalablytyped.org https://scalablytyped.org (like definitelytyped for Scala), https://slinky.dev/ https://slinky.dev/ (a small react wrapper), and https://material-ui.com/ https://material-ui.com/, which makes me work on the frontend at an incredible speed, while being confident on a low-bug rate.

kodefant 6y ago

I have been learning Haskell through IHP. It's the best and actually simplest web framework I have ever tried. The developer experience is the best I ever had for a MVC-style framework. And I got to learn Haskell without banging my head too much against the wall. Really enjoyed it :) I really needed something like IHP to get started with Haskell. It's fun and easy and the documentation is very easy to follow. I see some argue that they wish to make more custom choices regarding the setup. That is precisely what I don't want and that's why IHP is a great fit for me. In terms of simplicity I think the choice of supporting only Nix and Postgres actually are strengths at this point. That lets them streamline the development of the framework without supporting the minor preferences of every individual. And these choices should work really well for most web developers. Some may disagree on this, and maybe IHP is not for them, but I don't think it shouldn't discourage those who considers trying it out and form their own opinion. I was prepared for great hardships learning Haskell as most of the resources are very academic and I'm mainly just a simple application builder. IHP was just what I needed to fill that gap, and it made it really fun :) I am tweeting about the whole thing, coding Haskell for 100 days: https://twitter.com/larsparsfromage https://twitter.com/larsparsfromage

ljm 6y ago

I gave this a shot, to see if it'd be better than writing my API with Servant and then building a client separately. It looks really cool and there's been a lot of work put into it, so I had to see for myself. I kind of wish it didn't depend on Nix and Cachix and stuff like that, compared to deploying as a Stack template. I can see how it simplifies setup of a lot of the environment but considering the various issues I had trying to run it through WSL2, it left me at a point where I couldn't really understand what was going wrong. I'm back to messing around with Servant, but that's also because I'm not the target user for rapid web dev in this case. I want to learn Haskell my own way.

montmorency88 6y ago

IHP is the best web framework experience I have had. I think a lot of aspiring haskeller's will have worked their way through a text like Learn You a Haskell For Great Good or similar and then be looking to fool around with an actual project. IHP uses nix to cut out all the work of setting up ghc/stack/cabal which can be quite tricky for a beginner, it has just added haskell language server integration, it starts your postgres servers, it spares you from having to remember your SQL syntax, and means you can start writing haskell code instantly while getting immediate feedback on your hacking from GHCi and visually through the live reloading of the web app in your browser. I've found the [hsx||] quasiquotes quite fun to work with and type safety has sped up development by preventing bugs that can easily crop up when you're linking forms to databases. I like the design choices in IHP, and for me, at the moment, I like the focus on server side web app development, which encourages you to be more sparing/judicious in the use of javascript. With IHP being opinionated about the models/views and routing it means I can focus on integrating some of the other really cool haskell libraries that exist into web apps. (I'm also trying to keep a log of my experiences here on an https://ihpcafe.ihpapp.com https://ihpcafe.ihpapp.com if you want to read along with someone figuring out function type signatures ;) )

nsonha 6y ago

Jsx is a plague. What's wrong with simply nesting function calls like in elm and fsharp? Someone goes this far to learn a rather eccentric language you think they care about superficial familarities?